While potentially lucrative, mining can be extremely dangerous exercise. Large underground mines, in particular, present significant safety challenges due to the risk of cave-ins. Coal mines present even greater challenges due to the friable nature of coal and the constant leaking of explosive methane from the coal. It has been hypothesized that communication and locating technology could save miners' lives and mitigate the danger resulting from mine explosions, collapses, gas leaks, etc. Legislation since the disaster mandates communication and location technology so that miners can be located in the event of such disasters, yet such communication and location technology has heretofore been non-existent.
Presently, there are a number of different communications technologies that could be used in mines and similar locations, including: two way radios or “walkie-talkies”, wireline networks, “leaky feeder” networks, Personal Emergency Devices or Productivity Enhancement Devices (PEDs), and Through The Earth (TTE) systems. In general, none of the foregoing systems provide a complete range of desirable and satisfactory safety and operational features for a network in a mining or like environment.